The wind-power industry in China is blowing up a storm. From just six wind-turbine manufacturers in 2004, the China Wind Power Association estimates the country is now home to more than 70 companies. This represents a growth of at least 17 times in just six years.
Output is multiplying swiftly as well. Statistics from China’s Wind Power Material Equipment Network show 124 percent year-on-year growth in 2009 production to 10,129 wind turbines, generating a total of 13,803.2MW. This, in turn, is promoting development in the auxiliary industries such as blades, converters, pitch-control systems and inverters.
By working with local universities and overseas component suppliers, manufacturers aim to produce more affordable turbines that are 15-20 percent more efficient in generating electricity.
To make a mark in the export sector, China’s wind-turbine manufacturers are now investing in technology, certification and aftersales service upgrades. The majority of companies only started catering to overseas markets during the past two or three years.
In 2009, only four suppliers shipped out wind turbines internationally. These were Sinovel, Goldwind, Shanghai Electric and Changzhou New United. Sinovel exported 10 units to India. Goldwind sent 3 wind turbines to the US, while Shanghai Electric shipped 2 to Thailand. Changzhou New United manufactured 1 each for Thailand and the US.
At present, most locally made wind turbines cannot handle speeds that are too slow or too fast. The Chinese Wind Energy Association said a 1.5MW generator typically requires wind speed of at least 3 metres per second to start and 12.5 metres per second to generate electricity.
But at 25 metres per second, the turbines need to stop working because the electricity generated would be too much for the transformers to handle. Because of this limitation, suppliers focusing on large-capacity wind turbines are working with local universities to develop new technologies that can help improve stability and performance.
The Shandong Changxing Group is cooperating with the Shaanxi University of Science and Technology to produce high-speed synchronous generators with a brushless excitation system. Unlike the traditionally incorporated doubly-fed asynchronous generators and permanent magnet direct-drive systems, the newer technology can convert electricity even in extreme wind conditions.
Shandong Changxing is said to be the first in China to use such advanced systems, which can generate 15-20 percent more electricity than wind turbines adopting other technologies.